1.
Bring 1 litre of water to the boil. Add dry butter beans and boil for 2 to 3 minutes. Remove from heat and allow the beans to sit, covered, for 1 to 2 hours to soften. Drain and rinse until water runs clear, discarding bean water.
2.
In a soup pot, saute vegetables in olive oil until onions and celery are translucent. Add butter beans and saute for another 2 to 3 minutes.
3.
Meanwhile, bring 1 litre of water to the boil. Add the vegetable stock to the boiling water and stir until dissolved. Add stock to the sauteed vegetables and beans. Add remaining water and allow soup to simmer over a low heat for 1 to 1 1/2 hours. Serve steaming hot.